Method of abrading crankshafts



July 25, 1939.

F. POSTMA METHOD OF ABRADiNG CRANKSHAFTS,

Filed Sept. 17, 1937 gnaw 141cm Z72: Pasfmw WQ/M/MW v Patented July 2s,1939 ,z,1e1,a11"

METHOD or masonic onanxsnms roman, Bidsewood, N. .i. mama September 11,1931, Serial no. 164,390

2 Claims. (Cl. sh-@218) This invention relates to a method of abrading 1crankshafts, and has more particular reference to an improved method ofabrading the journals of engine crankshafts for the purpose of ,truingand/or polishing such journals after they have become unevenly worn andscored from any cause such as continued operation of the engine withdefective or.burned out bearing liners.

In truing and polishing the journals of engine 10 crankshafts, asheretofore practiced, it hasbeen necessary to completely removethe-crankshaft from t e engine and subject the crankshaft iour-.

nals ,to the action of grinding or lapping and/or polishing, toolsforming part ofv a; separate anddistinct lapping and polishingmachine.While efi'icient, such prior methods were extremely slow andcostly;

My method provides for abrading the journals of an engine'crankshaftwithout removing the same from the engine andwhile operativelyassociated with the main bearings of the engine block and with theconnecting rod bearings of the engine. I accomplish this by substitutingthinabrading liners of the type shown in my co-pending U. S. applicationSer. No. 164 filed September 17, 1937, now lgatent No. ,1 ated Dec. 27,1938, for the bearing liners of the main and connectingjiod bearings ofthe engine, and rotating the engine crankshaft so as to subject thejournals ofthe latter-tn the action of said abrading liners for truingand/or polishing said journals In this way, I am able to accomplisheflicient and accurate truing and polishing. of the crankshaftjournalsunder the actual conditions of engine operation and in an expeditiousand economical manner. As is the case with ordinary bearing liners, theabrading liners consist of a pair of semi-cylindrical members adapted toseat against the bore of thebearing and having secured or bonded totheir inner surfaces ,suitable granular abrading. material, such asemery or carborundum, which engages the crankshaft journal. The abradingliner sections are preferably of the same width or lengthas the 5bearing block and its cap? and are seated in con- 'tacting relation witheach other at their end or longitudinal edges. -As withbearing liners,the; abrading liners are preferably provided with means to assureretention of the same in the 50- correct positions with-respect to eachother and the bearing and against turning with the crankshaft journal,such as cooperating elements of the abrading liners and the bearings.The abrade ing liner sections are preferably constructed'of 55relatively. stiff and strong material, such as steel or other suitablemetal, which will efiectively resist distortion and destruction duringthe abrading operation.

Other objects and features of the invention will become apparent fromthe following descfip- 5 tion when considered in connection with theaccompanying drawing, in which:

, Figure 1 is a fragmentary sectional view showing an engine whosecrankshaft bearings are provided with abrading liners for abrading the10 crankshaftjournals in accordance with the present method.

Figure 2 is an enlarged fragmentary section taken on line 2-2 of Figuralat one side of a connecting rod bearing; and l5 Figure 3 is an. enlargedperspective view of one of the abrading liner sections employed incarrying out the present method as shown in Figures Referring in detailto the drawing, 5 indicates 20 an engine cylinder block having pistons 6reciprocable' in the cylinders thereof. As usual, the engine crankshaftI has a plurality :of spaced journals lmounted in bearings 9 oftheengine block 5, and the cranksof said crankshaft have 25 journals l0engaged in bearings 9w provided on the lower ends of connecting rods ll,to the upper ends of which the pistons 6 are attached. As is well knownin the art, each of the bearings 9 and 9:: includes a half hearing orhearing block 30 integral with thecylinder block- 5 and the connectingrod H as respectively indicated at l2 .and lid, and a separate, halfbearing Onbearing cap l3 and "a, detachably bolted as at l4; and

a tothe-bearing block I! andila, respectively. 5 i

As is also well known in the art, the bearings 9 and aa are usuallyprovided with thin bearing liners which are seated loosely in thebearings and clamped therein by the bolts. or Illa by n which theseveral sections of the bearings are 40 clamped together. Each of thesebearing liners usually consists oi! a pair of semi-cylindrical memberscomposed of a thin outer shell adapted to s'eatsagainst the bore ofthebearing and having bonded to its inner surface suitable anti-frictionmaterial which engages the crankshaft journal. The bearing linersectionsare usualls the same width or length as the bearing and areseated vin contacting relation with each other at their' end or lqngitua1 edges. In accorda oe with the present invention, the

bearing line s of the bearings 9 and 9a are re-.

' moved and abrading liners ccnforining in general size and shape tosaid bearing liners are substituted for. the latter,such abru'dingliners each consisting of a pair of semi-cylindrical members 15 composedof a thin outer shell adapted to seat against the bore ofthe bearing andhaving secured or bonded to its inner surface granular abrading materiall6 such as emery or carborundum which bears upon the crankshaftjournal.These abrading liner sections are the same width or length as thebearing and are seated in contacting relation with each other at theirend or longitudinal edges. Some suitable means such as is usuallyprovided in connection with the bearing liners, is provided to assureretention of the abrading liner sections in the correct positions withrespect to each other and the bearing. In

the construction illustrated by way of example,

this means consists of a lug I! struck outwardly from an end of eachabrading liner section and adapted to engage in a recess l8 of theassociated bearing member and to abut the adjacent end of the coactingbearing member as shown clearly in Figure 2. In this way the abradingliner sections are also held against turning with the crankshaft thejournals of the, crankshaft to the abradingaction of the .abradingliners. As the abrading operation proceeds, the abrading liners may be'adjusted by means of suitable shim plates interposed between the bearingand the abrading liners, or thickerabrading liners may be substitutedfor those initially placed in the bearings, if found necessary. In theinitial steps of the method, comparatively coarse abracling elementsorliners are employed, and after the crankshaft rotate the crankshaftfor a sufllcient length of time after the abrading liners are placed inthe bearings. Upon completing the polishing operation, the abradingliners are removed and the bearings are ready for reception of newbearing liners. All of these operations are performed without removingthe crankshaft from the engine and without the necessity of, a separateand distinct lapping and polishing means of expensive, construction. Bytruing and polishing the crankshaft journals in the engine block andconnecting rod bearings, accurate and efficient truing of the bearingsis insured in a most expeditious and economical manner. The abradinglinersmay be individually manufactured in proper sizes and grades,or'they may be formed at the point of operation by cutting suitableblanks from sheet abrading material especially manufactured for thepurpose.

From the foregoing description, it is believed that the nature of thepresent invention, as well as its advantages, will be readily understoodand appreciated by those skilled in the art.

What I claim as new is:

- 1. The method of abrading the main journal of an engine crankshaftwithout removing the latter from the engine, which consists insubstituting in the actual main engine bearing and for the bearing linersections of said bearing, thin abrading liner sections composed of thinouter shells of stiff strong sheet material having abrading materialbonded to their inner surfaces and correspending in formand size to saidbearing liner sections, securing said abrading liner sections in thehearing by the means which secures the bearing sections together so thatthe abrading material thereof contacts the surface of the crankshaftjournal, and rotating the crankshaft while in the engine so as tosubject its journal to the action of said abrading liner sections. I

2. The method of abrading the journal of an engine crankshaft, whichconsists in substituting in the actual crank pin bearing of the actualengin'e connecting rods-and for the bearing liner sections of saidbearing without removing said connecting rod or its piston from theengine, thin abrading liner sections composed of thin outer shells ofstiff strong sheet material having abrading material bonded to theirinner surfaces and corresponding in form and size to said hearing linersections, securing said abrading liner sections in the hearing by themeanswhich secures the bearing sections together so that their abradingmaterial contacts the surface of the crankshaft journal, and rotatingthe crankshaft so as to subject its journal to the action of saidabrading liner sections.

FRANK POSTMA.

